Chair with a combination back support and cover plate

ABSTRACT

A chair with a combination back support and cover plate is provided, which solves a burdensome affair that a user consistently holds up a back support folded on a seat until he or she sits on the seat, makes the back support automatically folded on the seat after use of the seat, to thereby enhance convenience of use, and prevents the back support from being unfolded upwards from the state where the back support has been folded on the seat due to wind, to thereby prevent the seat from being polluted due to dust or rainwater.

TECHNICAL FIELD

The present invention relates to a chair with a combination back supportand cover plate, and more particularly to, a chair with a combinationback support and cover plate in which a back support hinged with andsupported by a seat is automatically closely attached to the seat afteruse of the seat, to thereby prevent the seat from being polluted by dustor rainwater and to thus convenience management of the chair.

BACKGROUND ART

In general, there are chairs in a place where a number of people usesuch as a playground stand, an open theater, a park, etc.

Since the chairs which are installed in the above-described places areexposed in the outdoor environment, it is general to use chairs made ofplastic materials having an excellent durability. These chairs areconstituted by only a seat, or made of a seat and a back support whichare integrally formed, respectively.

However, since the chairs are exposed in the outdoor environment, dustmay be collected on the chairs, or the chairs may be wet due to the rainor snow, which causes it inconvenient to manage the chairs.

To solve the problem that the chairs are wet due to the rain or snowamong the above-described problems, a seat is formed with an inclinedstructure to prevent rainwater from being collected, or is formed withthe central portion positioned at a low position and having a drain holeto prevent rainwater from being collected. However, it is difficult toprevent the seat from being polluted due to foreign matters such asdust.

Thus, in order to prevent the seat from being polluted due to dust orrainwater, there has been introduced a chair having a structure that aback support hinged and connected with the rear end of a seat is used asa back support when the chair is used as a seat, and is used as a coverplate for the seat when the chair is not used as a seat.

However, in the case of a chair which employs a combined use of a backsupport as a cover plate for covering a seat of the chair in which theseat and the back support are hinged and connected with each other, auser should fold the back support to cover the seat with it. This causesdifficulties of management of chairs.

In order to solve the problems, the same applicant as that of thepresent invention developed and filed Korean Patent Application No.2001-16600 on 29 Mar. 2001 (Korean Laid-open Patent Publication No.2002-76617 published on 11 Oct. 2002), entitled “A chair with acombination back support and cover plate.” Here, a twist spring isinstalled in a hinge pin combined between a back support and a seat.Accordingly, in the case that a user stands up from a riding state onthe seat, the back support is automatically folded on the seat.

However, since the back support is always elastically supported on theupper surface of the seat by the twist spring, a user who wishes to siton the seat should raise up the back support with one hand until he orshe sits thereon.

DISCLOSURE OF INVENTION

To solve the above problems, it is an object of the present invention toprovide a chair with a combination back support and cover plate whichsolves a burdensome affair that a user consistently holds up a backsupport folded on a seat until he or she sits on the seat, makes theback support automatically folded on the seat after use of the seat, tothereby enhance convenience of use, and prevents the back support frombeing unfolded upwards from the state where the back support has beenfolded on the seat due to wind, to thereby prevent the seat from beingpolluted due to dust or rainwater.

It is another object of the present invention to provide a chair with acombination back support and cover plate which provides a seat with anelastic force to make a comfortable sitting state, and makes a backsupport being folded at low speed at the process of automaticallycovering the upper surface of the seat with the back support after useof the seat, to thereby prevent the chair from being damaged and causingnoise to be generated due to the mechanical shock which may happenbetween the back support and the seat at high speed.

To accomplish the above object of the present invention, according tothe present invention, there is provided a chair with a combination backsupport and cover plate comprising: a frame whose lower part is fixed toanother object; a seat which is installed on the upper portion of theframe; a back support which is hinged and connected with one end of theseat; a hinge portion which connects the seat and the back support bymeans of hinge connection; an elastic support unit which is installedbetween the seat and the frame, for elastically supporting the seat; aclosing unit which pulls the back support toward the seat if the frontend of the seat moves up by the elastic support unit when a user standsup from the seat; and a slow-downer which is connected with the hingeportion and the back support, to slow down the back support at lowspeed.

The closing unit comprises: a support unit which is installed in thelower middle portion of the seat so that the rear end of the seat movesup and down reversely when the front end of the seat moves up and downby the elastic support unit and a user's weight; a knob which protrudesin the lower end of the back support; and a stopper which is installedin the frame at the position where the knob contacts at the state thatthe back support has been unfolded.

The stopper is formed of a bolt which is combined with the frame bymeans of a screw so that a gap between the knob and the stopper can beadjusted, and whose one end contact the knob. Otherwise, the stopper isformed of a plate which is installed in the frame so as to adjust a gapbetween the knob and the stopper and contacts the knob, and a fixingunit which movably fixes the plate to the frame.

The closing unit comprises: a link whose one end is rotatably connectedwith the hinge portion and contacts the lower end of the back support; apushing rod on one end of which the fixing unit is formed and with theother end of which the link is connected; a spring which is mounted onthe pushing rod; a spring stopper to one end of which the frame is fixedand to the other end of which one end of the spring is fixed, to therebysupport the pushing rod; a rod stopper which is connected with the otherend of the spring and fixed to the pushing rod; a hook which isinstalled in the frame and is connected with the fixing unit which isformed in one end of the pushing rod; a hook spring which is connectedbetween one end of the hook and the frame, for pulling the hook towardthe seat; and a hook release unit which is installed below the seat andseparates the hook from the fixing unit in the pushing rod by a user'sweight when a user sits on the seat.

The present invention further comprises a limit unit which limits amoving range by the elastic support unit between the front end of theseat and the frame.

The present invention further comprises a magnet or magnetic body whichis installed in opposition to each other in both the seat and the backsupport, respectively.

The elastic support unit comprises: a housing to the upper end of whichthe fixed frame is fixed; a spring which is installed in the inside ofthe housing; and a pusher which is directed toward the seat by thespring.

The elastic support unit is formed of at least one spring whose one endis fixed to the frame and whose other end is fixed to the seat.

The slow-downer comprises: a casing whose one side is combined with theback support, and on one side of the inner surface of which an oilblocking wall is formed; a fixed unit on the outer circumferentialsurface of which one end of the oil blocking wall contacts and with theinner circumferential surface of which the hinge portion is combined,and on the outer circumferential surface of which at least one blade isformed to maintain a gap from the inner circumferential surface of thecasing; an oil which is filled in a space formed between the casing andthe fixed unit; and a seal unit which seals both side ends between thecasing and the fixed unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and advantages of the present invention willbecome more apparent by describing the preferred embodiment thereof indetail with reference to the accompanying drawings in which:

FIG. 1 is a perspective view showing a state where a back support isfolded on a seat in a chair with a combination back support and coverplate;

FIG. 2 is a perspective view showing a state where a back support isunfolded on a seat in a chair with a combination back support and coverplate;

FIG. 3 is a front view for explaining a chair with a combination backsupport and cover plate according to a first embodiment of the presentinvention;

FIG. 4 is a side view showing a state where aback support is folded on aseat in a chair with a combination back support and cover plateaccording to the first embodiment of the present invention;

FIGS. 5 and 6 are side views for explaining a process that a backsupport is unfolded in a chair with a combination back support and coverplate according to the first embodiment of the present invention;

FIG. 7 is a side view showing a state where aback support is completelyunfolded in a chair with a combination back support and cover plateaccording to the first embodiment of the present invention;

FIG. 8 is a side view for explaining structure of an elastic supportunit in a chair with a combination back support and cover plateaccording to a second embodiment of the present invention;

FIG. 9 is a cross-sectional view for explaining structure of aslow-downer in a chair with a combination back support and cover plateaccording to the second embodiment of the present invention;

FIG. 10 is a partial perspective view for explaining position ofinstalling the slow-downer in a chair with a combination back supportand cover plate according to the second embodiment of the presentinvention;

FIG. 11 is a front view for explaining a chair with a combination backsupport and cover plate according to a third embodiment of the presentinvention; and

FIG. 12 is a bottom view for explaining a chair with a combination backsupport and cover plate according to the third embodiment of the presentinvention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinbelow, a chair with a combination back support and cover plateaccording to the present invention will be described with reference tothe accompanying drawings.

In the accompanying drawings, FIGS. 1 through 7 are provided to describea chair with a combination back support and cover plate according to afirst embodiment of the present invention, FIGS. 8 through 10 areprovided to describe a chair with a combination back support and coverplate according to a second embodiment of the present invention, andFIGS. 11 and 12 are provided to describe a chair with a combination backsupport and cover plate according to a third embodiment of the presentinvention.

1. FIRST EMBODIMENT

As shown in FIGS. 1 through 7, in a chair with a combination backsupport and cover plate according to a first embodiment of the presentinvention, a support leg 2 is fixed on the ground. On the upper portionof the support leg 2 is installed a main frame 4 formed of a horizontalportion 6 and an inclined portion 8 which is extended with an inclinedstructure upwards from the rear end of the horizontal portion 6. On theupper end of the inclined portion 8 in the main frame 4 is installed aback support bar 10 for supporting a back support 26 horizontally in thelengthy direction.

Also, a seat 20 is disposed on the upper portion of the horizontalportion 6 in the main frame 4, and the back support 26 is hinged withthe rear end of the seat 20 by a hinge pin 32. On the bottom of thefront end of the seat 20 is formed a seat groove 22 in and from which athird support bar 16 to be described later is attached and detached. Onthe rear surface of the back support 26 is formed a back support groove28 in which the back support bar 10 is safely mounted.

Also, on the central upper portion of the main frame 4 is fixedlycombined a second support bar 12 which supports the seat 20 andsimultaneously rotates the front side of the seat 20 up and down to playa role of a rotational axis. The second support bar 12 is horizontallyfixedly supported so as to be perpendicular with the horizontal portion6. The seat 20 is safely mounted on the upper portion of the secondsupport bar 12.

Here, the seat 20 is rotatably combined with the second support bar 12by means of a first clip 14 which is combined on the lower surface ofthe seat 20. This rotational structure is embodied by forming a groovewith a curvature corresponding to the second support bar 12 at thecentral portion of the first clip 14 so that the lower outercircumferential surface of the second support bar 12 is supported on theinner circumferential surface of the first clip 14, at the state theformer contacts the latter.

Further, a third support bar 16 is fixed on the front upper portion ofthe horizontal portion 6 in the main frame 4 so as to be perpendicularwith the horizontal portion 6. The third support bar 16 is formed sothat the upper surface of the third support bar 16 is inserted into orreleased from a seat groove 22 when the seat 20 rotates around thesecond support bar 12.

Meanwhile, a second clip 18 which is fixed on the bottom surface of theseat 20 is combined on the lower side of the seat groove 22 in the seat20 so that both ends of the second clip 18 is adjacent to the seatgroove 22. In this case, a groove portion corresponding to a curvatureof the third support bar 16 is formed in the second clip 18 so that thelower surface of the third support bar 16 is inserted into and releasedfrom the central portion of the second clip 18.

In this case, the groove portion formed in the second clip 18 is formedin depth deeper than that of a groove portion formed in the first clip14. The depth of the groove portion is established in depthcorresponding to a predetermined angle for rotating the seat 20.

Further, the second clip 18 plays a role of limiting the seat 20 so thatthe front side of the seat 20 is prevented from rotating upwards by apredetermined angle or more around the second support bar 12 by means ofan elastic support unit 40 to be described later.

Meanwhile, a number of fixed frames 34 are fixedly disposed at apredetermined interval in the lower portion of the third support bar 16and the second support bar 12 so that the number of fixed frames 34 areperpendicular with the third support bar 16 and the second support bar12.

Here, on the fixed frames 34 is formed a female screw portion 36 on therear end of which a female screw is formed, respectively. A stopper 60to be described later is engaged with the female screw portion 36.

Also, a plurality of elastic support units 40 which are installed on theplurality of fixed frames 34 are installed to elastically support thefront lower surface of the seat 20 upwards. Accordingly, a user can usethe seat 20 comfortably.

As shown in FIG. 5, each of the elastic support units 40 includes abracket 42 which is installed in either side of the fixed frames 34. Acover 44 is engaged on the upper portions of the brackets 42 by means ofa number of coupling bolts 46. Further, with the lower central portionof the cover 44 is combined a hollow spring case 48 in the inner side ofwhich a coil spring 50 is inserted.

Also, each of the elastic support units 40 includes a pusher 52 whichpenetrates the lower end of the cover 44 and the spring case 48 insequence vertically. On the upper end of the pusher 52 is formed apusher head 54 which is mounted into a head groove 24 in the seat 20.

The pusher 52 is coupled with the cover 44 and the spring case 48slidably at the state where the pusher 52 penetrates the cover 44 andthe spring case 48 in sequence. A protruded pressing portion is formedaround the central portion of the pusher 52. Accordingly, the protrudedpressing portion is elastically supported on one side of the spring 50which is inserted in the spring case 48. As a result, the pusher head 54pushes the front portion of the seat 20 upwards at the state where thepusher head 54 closely supported on the inner circumferential surface ofthe head groove 24 in the seat 20.

Meanwhile, in the lower portion of the back support 26 is protrudinglyinstalled a knob 30 which supplementarily assists a main function of thechair with a combination back support and cover plate according to thepresent invention.

Also, a stopper 60 by which the lower end of the knob 30 is supported isengaged in a female screw portion 36 which is positioned in the rear endof the fixed frame 34. The stopper 60 has a structure that a distancefrom the stopper 60 to the knob 30 can be adjusted.

That is, the stopper 60 includes a male screw portion 62 which isengaged with the female screw portion 36 in the fixed frame 34, a nut 66which is engaged with the male screw portion 62 positioned in the lowerside of the female screw portion 36, to thus limit rising of the malescrew portion 62, and a stopper head 64 which is engaged with the malescrew portion 62 which is positioned in the upper portion of the femalescrew portion 36 to thus support the bottom surface of the knob 30.

Also, a permanent magnet 72 is fixed in the inner surface of the frontupper portion of the back support 26, and a steel iron plate 70 which isinstalled in opposition to the permanent magnet 72 is fixedly providedin the front upper surface of the seat 20 to adhere to the permanentmagnet 72. Accordingly, when the back support 26 is folded on the seat20, the steel iron plate 70 is attached to the permanent magnet 72, tothereby prevent the back support 26 from being opened due to wind andthus prevent the seat 20 from being polluted.

In the case of the chair with a combination back support and cover plateaccording to the first embodiment of the present invention having theabove-described structure, when the seat 20 is raised up as shown inFIG. 5 in order to sit on the seat 20 at the state where the backsupport 26 is closed on the seat 20 as shown in FIG. 4, the knob 30 inthe back support 26 is supported by the stopper head 64. In this state,although a user releases his or her hand from the back support 26, anangle formed by the back support 26 and the seat 20 is maintained atsubstantially 90 degrees upright.

Thus, even if a user raises up the back support 26 and then releases hisor her hand therefrom, the back support 26 is not closed on the seat 20,that is, the back support 26 is not folded on the seat 20.

Therefore, the chair with a combination back support and cover plateaccording to the present invention solves inconveniences that userssuffer from the conventional foldable chair employing the back support26 that should be held by at least one hand, to thereby greatly enhanceconveniences and quality of products.

Meanwhile, when a user sits on the seat 20 at the state where the backsupport 26 is opened or unfolded as shown in FIG. 5, the front side ofthe seat 20 is descendant around the second support bar 12 and theelastic support unit 40 presses the pusher 52 to compress the spring 50,as shown in FIG. 6. As a result, the upper portion of the third supportbar 16 contacts and is supported on the inner circumferential surface ofthe seat groove 22, to accordingly limit rotation of the seat 20.

Then, as the seat 20 is rotated around the second support bar 12, theback support 26 positioned in the rear end of the seat 20 is raised upas shown in FIG. 6, and thus the knob 30 in the back support 26 goes farfrom the stopper head 64.

Therefore, when a user who wants to sit on a seat 20 leans against theback support 26, the back support 26 is rotated further in the reardirection therefrom. Thus, a back support groove 28 is supported by aback support bar 10 and simultaneously the knob 30 contacts and issupported on the stopper head 64. As a result, rotation of the backsupport 26 is limited, to thereby have a user sit on the seat 20 whilecomfortably leaning against the back support 26.

Meanwhile, when a user stands up from the seat 20 after use of the seat20, the compressed spring 50 is restored to allow the pusher 52 and thepusher head 54 to rise up. Accordingly, the front end of the seat 20 isrotated upwards and thus the lower end of the back support 26 isdescendant around the second support bar 12. As a result, the knob 30 ispushed by the stopper head 64 and the back support 26 is rotated aroundthe hinge pin 32. Then, when an angle formed by the seat 20 and the backsupport 26 is acute, the back support 26 is folded due to its own weightas shown in FIG. 4.

As described above, since the present invention allows the back support26 to be automatically folded on the seat 20, at the same time when auser stands up from the seat 20, it facilitates management of the seat.

Also, since the elastic support unit 40 provides the seat 20 withelasticity, shock due to sitting is reduced to thereby allow a user tofeel comfortable at the time of sitting. Also, the elastic support unit40 mitigates shock occurring when the back support 26 is closed on theseat 20 due to its own weight.

2. SECOND EMBODIMENT

As shown in FIGS. 8 through l0, a chair with a combination back supportand cover plate according to a second embodiment of the presentinvention, includes an elastic support unit and a stopper differing fromthose of the first embodiment and further includes a slow-downerinstalled between the hinge pin 32 and the back support 26. The othercomponents other than the above-described elastic support unit, stopper,and slow-downer in the second embodiment are very similar to those ofthe first embodiment.

An elastic support unit is installed between a fixed frame 34 and a seat20, and uses a spring 40 a which is a kind of a compression spring.

That is, one end of the spring 40 a contacts the lower surface of theseat 20, and the other end of the spring 40 a is fixed to the fixedframe 34.

The elastic support unit according to the second embodiment is simplerin construction than the elastic support unit 40 of the first embodimentbut the former provides the same effect as that of the latter, tothereby enhance productivity.

As shown in FIG. 8, the stopper according to the second embodimentincludes a bolt 67 which is coupled with a main frame 4 by means of ascrew, and a plate 68 which is bent so as to contact the knob 30 at anappropriate angle and coupled with the fixed frame 34 by the bolt 67.

A lengthy groove is formed at the portion where the plate 68 is engagedwith the bolt 67, and thus position of the plate 68 can be changed tothereby adjust a gap between the knob 30 and the plate 68.

As shown in FIGS. 8 and 9, the slow-downer uses oil 90 in order toprevent the back support 26 from being closed or folded on the seat 20with a mechanical shock due to its own weight. Accordingly, since theback support 26 is slowly closed or folded on the seat 20 by use of oil90, damage or noise generation due to shock of the back support 26 canbe prevented.

As shown in FIG. 8, the slow-downer includes a casing 80, a fixedportion 83 which is fixed to the hinge pin 32 and coupled with theinside of the casing 80, and oil 90 filled in the space formed betweenthe casing 80 and the fixed portion 83.

The casing 80 is cylindrically formed. A blocking wall 82 is formed inone side of the inner circumferential surface of the casing 80 and afixed plate 81 which is fixed to the rear surface of the back support 26is formed in one side of the outer circumferential surface of the casing80.

The hinge pin 32 is fixed to the center of the fixed portion 83. Theouter circumferential surface of the fixed portion 83 are formed tocontact the blocking wall 82. In one side of the circumferential surfaceof the fixed portion 83 are formed three blades 84 maintaining a smallgap (G) from the inner circumferential surface of the casing 80, inwhich two blades are distant by one-hundred eighty (180) degrees fromeach other and the other blade is formed between the two 180-degreedistant blades.

In this embodiment, three blades 84 are formed, but since acorresponding force should be sufficiently formed by means ofrelationship with the oil 90, so that the back support 26 becomes foldedslowly, the structure of the blades can vary according to weight of theback support 26.

Both side ends of the casing 80 and the fixed portion 83 are sealed byfirst and second caps 86 and 87. Here, since the casing 80 is rotatablycombined with the fixed portion 83, the first and second caps 86 and 87are sealed by O-rings 88, 89, and 89 a, respectively.

In this embodiment, a descending speed of the back support 26 can bedetermined by a gap (G) formed between the inner circumferential surfaceof the casing 80 and the blades 84. However, if the gap (G) is constant,the descending speed of the back support 26 can be slowly descendant bythickening adhesiveness of the oil 90, or quickly descendant by thinningadhesiveness of the oil 90.

3. THIRD EMBODIMENT

As shown in FIGS. 11 and 12, a chair with a combination back support andcover plate according to a third embodiment of the present invention,includes a closing unit which closes a back support 26 differing fromthose of the first and second embodiments. The other components otherthan the above-described closing unit in the third embodiment are verysimilar to those of the first and second embodiments.

The closing unit in the third embodiment includes a link 91 a whose oneend is rotatably connected with the hinge pin 32 and contacts a knob 26a formed in the lower end of the back support; a pushing rod 91 on oneend of which the fixing unit 91 b is formed and with the other end ofwhich the link 91 a is connected; a spring 92 which is mounted on thepushing rod 91; a spring stopper 92 a to one end of which the frame 96is fixed and to the other end of which one end of the spring 92 isfixed, to thereby support the pushing rod 91; a rod stopper 91 a whichis connected with the other end of the spring 92 and fixed to thepushing rod 91; a hook 94 which is installed in the frame 96 and isconnected with the fixing unit 91 b which is formed in one end of thepushing rod 91; a hook spring 94 a which is connected between one end ofthe hook 91 and the frame 96, for pulling the hook 94 toward the seat20; and a hook release unit 95 and 95 b which is installed below theseat 20 and separates the hook 94 from the fixing unit 91 b in thepushing rod 91 by a user's weight when a user sits on the seat.

The hook release unit includes a plate 95 connected with the lower endof the seat 20, and a pusher 95 a which is connected with the plate 95positioned in correspondence to the hook 94, for pushing the hook 94downwards.

The fixed unit 91 b is installed in one end of the pushing rod 91. Inorder to have one end of the pushing rod 91 easily engaged with the hook94 when the pushing rod 91 moves toward the front end of the seat 20,the fixing unit 91 b is installed toward one end of the pushing rod 91in the form of a streamline, in which each end of the fixing unit 91 bis hinged so that the hook 94 is engaged with one side of the fixingunit 91 b and a tensile spring 93 which is connected with the springstopper 92 a is installed in the other side thereof, to thereby pull thefixing unit 91 b.

In the third embodiment of the present invention, an elastic member 97which is an elastic support unit is installed across both ends of theframe 96 and between the plate 95 installed toward the front end of theseat 20 and the front end of the seat 20, above the frame 96. Theelastic member 97 is made of rubber or synthetic resin having anexcellent elastic restoring force, differently from the springs used inthe first and second embodiments.

INDUSTRIAL APPLICABILITY

As described above, in the case of the chair with a combination backsupport and cover plate according to the present invention including aseat and a back support, the seat is protected by using the back supportwhen the seat is not occupied by a user. The present invention providesa seat with an elastic force to make a comfortable sitting state, andmakes a back support being folded at low speed at the process ofautomatically covering the upper surface of the seat with the backsupport after use of the seat, to thereby reduce a management cost ofthe chairs.

Also, the present invention prevents the chair from being damaged andcausing noise to be generated due to the mechanical shock which mayhappen between the back support and the seat when the back support isclosed on the seat at high speed by its own weight.

As described above, the present invention has been described withrespect to particularly preferred embodiment. However, the presentinvention is not limited to the above embodiment, and it is possible forone who has an ordinary skill in the art to make various modificationsand variations, without departing off the spirit of the presentinvention. Thus, the protective scope of the present invention is notdefined within the detailed description thereof but is defined by theclaims to be described later and the technical spirit of the presentinvention.

1. A chair with a combination back support and cover plate comprising: aframe whose lower part is fixed to another object; a seat which isinstalled on an upper portion of the frame; a back support which ishinged and connected with one end of the seat; a hinge portion whichconnects the seat and the back support by means of a hinge connection;an elastic support unit which is installed between the seat and theframe, for elastically supporting the seat; a closing unit which pullsthe back support toward the seat if the front end of the seat moves upby the elastic support unit when a user stands up from the seat; and aslow-downer which is connected with the hinge portion and the backsupport, to slow down the pulling of the back support during the pullingof the back support towards the seat.
 2. The chair with a combinationback support and cover plate according to claim 1, wherein the closingunit comprises: a support unit which is installed in the lower middleportion of the seat so that the rear end of the seat moves up and downreversely when the front end of the seat moves up and down by theelastic support unit and a user's weight; a knob which protrudes in thelower end of the back support; and a stopper which is installed in theframe at the position where the knob contacts at the state that the backsupport has been unfolded.
 3. The chair with a combination back supportand cover plate according to claim 2, wherein the stopper is formed of abolt which is combined with the frame by means of a screw so that a gapbetween the knob and the stopper can be adjusted, and one end of thestopper can contact the knob.
 4. The chair with a combination backsupport and cover plate according to claim 2, wherein the stopper isformed of a plate which is installed in the frame so as to adjust a gapbetween the knob and the stopper and contacts the knob, and a fixingunit which movably fixes the plate to the frame.
 5. The chair with acombination back support and cover plate according to claim 1, whereinthe closing unit comprises: a link whose one end is rotatably connectedwith the hinge portion and contacts the lower end of the back support; apushing rod on one end of which a fixing unit is formed and with theother end of which the link is connected; a spring which is mounted onthe pushing rod; a spring stopper to one end of which the frame is fixedand to the other end of which one end of the spring is fixed, to therebysupport the pushing rod; a rod stopper which is connected with the otherend of the spring and fixed to the pushing rod; a hook which isinstalled in the frame and is connected with the fixing unit which isformed in one end of the pushing rod; a hook spring which is connectedbetween one end of the hook and the frame, for pulling the hook towardthe seat; and a hook release unit which is installed below the seat andseparates the hook from the fixing unit in the pushing rod by a user'sweight when a user sits on the seat.
 6. The chair with a combinationback support and cover plate according to claim 1, further comprising alimit unit which limits a moving range by the elastic support unitbetween the front end of the seat and the frame.
 7. The chair with acombination back support and cover plate according to claim 1, furthercomprising a magnet or magnetic body which is installed in the seat andthe back support, respectively.
 8. The chair with a combination backsupport and cover plate according to claim 1, wherein the elasticsupport unit comprises: a housing to the upper end of which the fixedframe is fixed; a spring which is installed in the inside of thehousing; and a pusher which is directed toward the seat by the spring.9. The chair with a combination back support and cover plate accordingto claim 1, wherein the elastic support unit is formed of at least onespring whose one end is fixed to the frame and whose other end is fixedto the seat.
 10. The chair with a combination back support and coverplate according to claim 1, wherein the slow-downer comprises: a casingwhose one side is combined with the back support, and on one side of aninner surface of which an oil blocking wall is formed; a fixed unit onthe outer circumferential surface of which one end of the oil blockingwall contacts and with the inner circumferential surface of which thehinge portion is combined, and on the outer circumferential surface ofwhich at least one blade is formed to maintain a gap from the innercircumferential surface of the casing; oil filled in a space formedbetween the casing and the fixed unit; and a seal unit which seals sideends between the casing and the fixed unit.